Panicum miliaceum is a tillering clonal species with profuse roots, and is widespread in northern China. The species has been regarded as an ideal plant for experiments with nutrient patches due to its rapid growth. Early June 1999, plastic boxes (18cm×18cm ×30cm) were put at the center of paper boxes (42cm×35cm×30cm), and the plastic boxes and the space between the plastic boxes and the paper boxes were fully filled with a mixture of sand and compound fertilizer in various proportions. Each growth containe...